Granted, your device is likely already locked down with a passcode. So anyone looking to gain sensitive information on your phone still has to get past the main gate. However, multiple checkpoints are always good for security, so password-protecting certain notes is still worth doing. In the Notes app on iOS, you can even choose which notes to lock down.

To get started, open up the Notes app on your iPhone and swipe to the left on a specific note that you want to lock down. In this case, I’m going to put a password on this note containing the serial numbers to some of my devices.

This will bring up several options, but you’ll want to tap on the gray lock icon.

You’ll be taken to another screen, where you’ll enter in a password that will be used to unlock all and any notes that you want to password-protect. Enter in a password (and verify it by entering it in again) and then hit “Done” in the top-right corner.

You’ll be taken back to the Notes app, where you’ll now see a padlock appear next to the note. It will start off in an unlocked state.

To lock the note, tap on “Lock Now” at the very bottom of the screen.

The note will now be locked and all of the preview text that you were able to see earlier will be gone and replaced with either “Locked” or “Unlocked”.

When you go to open up a note that is locked, tap on “View Note”.

If you have Touch ID, you can simply use that to unlock the note, but you’ll also have the option of typing in the password.

After that, you’ll have access to your note. Once you’re done with it, you can tap on the unlocked padlock icon in the upper-right corner of the screen to lock it back up.

You can also go back to the main screen of the Notes app and tap on “Lock Now” at the bottom (like you did before) to lock all unlocked notes at once.

To remove password protection entirely from a note, swipe on it like before and tap on the gray lock icon again.

You’ll be asked to use Touch ID or enter in the password to verify (just like if you were unlocking a note to view it), but after that the note will now be completely unlocked for good.

Keep in mind that if you sync notes across your various Apple devices using iCloud, locking a note will also lock it on your other devices, and vice versa.